Service indicator



ug- 24, 1965 H. A. sHERwooD 3,202,315

SERVICE INDICATOR Original Filed Nov. 22, 1961 3 Sheets-Sheet 1 204 INVENTOR, AfA/,ey A. wen/aap Aug. 24, 1965 H. A. sHERwooD 3,202,315

SERVICE INDICATOR Original Filed Nov. 22, 1961 3 Sheets-Sheet 2 LEE- 4- /47/fll, //52 Aug. 24, 1965 H. A. sHERwooD SERVICE INDICATOR i s sheets-sheet 3 Original Filed Nov. 22, 1961 rs-LEA..

rneaz 5w.; Haase, nes g Jbfn United States Patent O 3,202,3't5 SERVER INDl-CATR Henry A. Sherwood, Short Hills, NSE., assigner to US. Servicator Corp., Plainview, NY., a corporation or? Deiawaie Continuation of appiication Ser. No. 154,311, Nov. 22, i961. This application Aug. t3, '1963, Ser. No. 301,864 1.6 Claims. {Cln 22d-15) This application is a continuation in part of my copending application Serial No. 83,346 tiled lan. 17, 1961 and is a continuation of my abandoned application Serial No. 154,3l1 tiled November 22, i961. The former application discloses an electro-mechanical prime mover cyclically operable to achieve a timed action or series of timed actions while in the latter application the prime mover is set forth in combination with novel means for ejecting a service indicating card from a stack of cards stored in a compartment.

Power units of the type to which the present invention relates have been suggested heretofore but so far as can be determined they have proved to be impractical and unreliable because of variables which exist or develop in the inter-relation of theirelectrical and mechanical functions. The present invention overcomes this undesirable defect of the prior art by providing a motor constructed to assure its proper and accurate functioning, which is attained 'oy the provision of means tor establishing a detinite inter-relation of all of its operating parts to effect a fixed sequence of action of these parts.

To this end, the present invention in its broad aspects contemplates a power unit having drive driven means connected by power transmission means, wherein the drive means comprises a bimetallic element mounted to move in response to the application of heat thereto, and means for applying the heat intermittently to effect a cyclic movement of the bimetallic element upon its being successively heated and then allowed to cool during each cycle.

More specifically, the invention provides a bimetallic element surrounded by an electric resistance coil arranged in an electric circuit which is opened and closed by a rockable over-center spring switch, the switch kin turn being actuated by the movement of the bimetallic element to effect rocking of the switch from on to oit position, and vice versa. The bimetallic element is equipped with a pawl which engages with the Ateeth on a ratchet wheel so that when the element moves responsive to being heated by the resistance coil, movement of the element is translated through t le pawl to turn the ratchet wheel. An arm secured to the bmetailic eiement and movable with it serves as an anchor for one end of the switch spring, and when the element has moved suthciently to rotate the ratchet wheel through a distance equal to the pitch of the tooth engaged -by the pawl, the arm to which the spring is anchored will have moved a distance sufficient to carry the spring beyond center, whereupon it exerts a force which rocks the switch to break the electric circuit and allow the birnetallic element to cool and return to its original position. In so doing, the spring is returned past center, whereupon it rocks the switch back to its original position to reestablish the electric Contact and commence next cycle of operation.

it is a prime feature of the invention that the power unit achieves its reliability from the concept of an interrelated adjustability of its operating parts. Thus, the bimetallic element is adjustable to place it under tension or pre-lead it beyond the point where it is affected by the temperature oi the atmosphere. Such adjustment determines the initial positions of the element, the driving pawl, the ratchet wheel and the switch spring anchoring arm, and in this condition of the parts the switch spring ICC is accurately located on the arm, the on and ott positions or" the switch are adjusted to proper locations, and a holding pawl is adjusted relative to the teeth of the ratchet wheel, its function being to prevent rotation of the wheel in a direction reverse to that in which it is being` driven.

in order not to upset the settings of the holding pawl and switch spring and also to insure predictable operation pre-loading of the bimetallic element is done at the anchored end thereof. That is, means are provided to adjust the anchored end of the bimetal relative to its support while the free end of the bimetal rests against a iixed stop when the bimetal is cool. With this arrangement the free end ot the bimetal deilects the same distance during each cycle regardless of the degree of pre-loading.` .Each card in the stack is provided with a keying notch which cooperates with a keying formation in the magazine to assure that the stack is properly oriented. Proper orientation is essential since the cards in the stack are arranged in a programmed sequence. That is, each card does not contain the same servicing instructions. For example, after titty hours of operation a card is ejected to indicate that oil is to be changed and after four hundred hours a card is ejected to indicate that spark plugs are to be cleaned.

The keying notch serves a dual function by cooperating with a hold back spring to prevent the card from being fully ejected upon the sudden release of the actuator arm spring energy. With the card fully within the magazine the hold back spring is disposed within the keying notch. As the card is being ejected the spring engages the card edge portion dening one end of the notch. The` momentum of the card being ejected is not sufficient to overcome the spring pressure so that card movement is arrested with the .card partially ejected.

Since the card is partially ejected it is conspicuous yet it cannot be accidentally dislodged. However, the spring pressure is readily overcome as the partially ejected card is intentionally removed by the servicemen.

The typical device to be serviced is an automobile engine and related parts requiring lubrication. The power unit is energized only when the automobile ignition is on. Thus, the service indications will be based upon time of engine operation rather than upon the traditional yardstick of miles driven. The traditional yardstick is merely for average conditions and does not take into account the occasions when the engine is driven at either very light or very heavy loads for the entire service period. City driving, since it is more taxing upon an automobile engine, requires that servicing be performed after fewer miles have been driven than in the case of road driving which subjects the engine to relatively slight wear. With time as the measuring standard fewer city miles than country miles will have been driven in the periods between servicings.

Further application for the instant invention is found in the servicing of fork lifts, mobile cement mixers, travcling cranes and the like. In each of these devices a major portion of engine wear is unrelated to mileage.

Accordingly, a primary object of this invention is to provide a novel construction for a bimetal power unit. Another object is to provide a novel construction for a service indicating device which is essentially responsive to time of operation rather than mileage.

Still `another object is to provide a novel service indicating device in which there is a mechanism containing programmed servicing instructions with appropriate portions of these instructions being ejected at predetermined times during the life of the machine to be serviced.

Yet another object is to provide a device of this type in which a cam is utilized to load an energy storing means j and thereafter release the stored energy to enable a useful function to be performed at the desired time.

A further object is to provide a service indicating device whose operation is effectively integrated so that varying operating conditions are automatically considered.

A still further object is to provide a device of this type having a bimetal drive means with provisions for preloading being at the anchoring end of the bimetal.

These as well as other objects of this invention shall become readily apparent after reading the following descriptionof the accompanying drawings in which:

FIGURE 1 is a front elevation of the device with the cover removed showing the working structure of the power unit when the bimetal is cool.

FIGURE 2 is a view similar to that of FIGURE 1 showing the position of the elements when the bimetal is fully heated.

FIGURE 3 is a fragmentary view similar to FIGURE 1 with the one of the toothed wheels removed to reveal the toothed wheel which drives the cam and is also utilized for resetting purposes.

FIGURE 4 is a side elevation of the device of FIG- URE 1 with the power unit cover shown in phantom.

FIGURE 5 is a rear elevation of the mechanism with the cover open and the magazine is empty.

FIGURE 6 is a plan view of one of the service indicating cards with the servicing indicia removed.

FIGURE 7 is an exploded perspective illustrating the mounting of the device.

FIGURE 8 is a schematic illustrating the service indicator connected in operative relationship to an engine.

FIGURE 9 is a cross-section taken through line 9 9 of FIGURE 1.

FIGURE 9A is a fragmentary side elevation showing the pusher while it is moving a card.

Now referring to the figures, the device of the present invention is a very simplified form of electro-mechanical power unit comprising a drive means It), a driven means 11 and power transmission means 12 connecting the drive means to the driven means. The parts comprising the drive means I@ are mounted on the back wall 113 of magazine 100 to which they are secured in any suitable manner such as by screws entering from behind the wall 13 and therefore not visible in the drawing. A board of insulating material 15 is secured to bracket sections 15a, 15b and anchored to section 15a, as by screws 16, is one leg 17 of a bimetallic element I8. The other and longer leg 19 of the element 1S depending for 'a considerable distance below the bracket section 15a in a position to swing relative to the fixed leg 17. Secured to the bracket sections 15b and 15e one at each section thereof, are screw 26 and arm 21 which act as stops and may be identified as on stop 2t) and ott stop 21.

Bracket 22 is secured to wall 13 below and in spacedapart relation to bracket 15a, 15b, 15C and at its lower forward edge bracket 22 is formed with an arm 23 bent outwardly relatively to wall 13 at a right angle to the bracket 22 and arranged to engage the leg 19 of the bimetallic element 18 near its free end for the purpose of providing a xed reference for leg 19 under a predetermined pre-loading tension for a purpose to be explained more fully hereinafter. Secured to the leg 19 of the bimetallic element 118 is an arm 2.7 arranged to extend rearwardly or toward and alongside but out of contact with the bracket 22. As will be observed, the bottom edge of the arm 27', from its free end and throughout approximately one-half of its length, is formed with transverse depressions 28.

. The upper edge of the bracket 22 is formed with a V-shaped notch 29 adapted to serve as a pivot seat for a switch arm 30. As shown in FIGURE 1, the switch arm 30 extends from the notch 29 upwardly between stops and 21 and its upper end engages the under surface of a flexible spring contact EI'which is secured to or made 4as a part of an electric conductor secured to the insulating sheet 15. Switch arm 39 is held on the V-shaped seat 29 by a tension spring 32 having one end 33 engaged in an aperture 34 formed in the switch arm and its lower hook-shaped end 34a engaging member 35. The latter includes an aperture through which 'arm 27 extends with a portion of member 35 engaged in one of the depressions 2S on the arm 27, spring 32 being under slight tension to exert a downward pull on the switch arm 30. The arrangement is what is commonly known as a snap acting over-center spring switch. Motion of arm 27 is stabilized by member 25 seated in V-notch Z6 of bracket 22 and arm 27 extending through an aperture of member 25.

As already stated, the contact 3i is secured to a conductor fastened to the block 15, and this conductor is connected by lead MII to another contact of insulator I5. Lead is secured at one end thereof to terminal contact MI5 while the other end thereof is connected to still another terminal of insulator 1.5. This last terminal is connected through lead 1% to one coil of resistance heater coils 38a, 33 surrounding the leg 19 of the bimetallic element 13, the opposite or lower end of this coil being connected through lead 102 to a further terminal of insulator I5. The opposite end of the coil is also connected to one end of another coil surrounding bimetal leg 19. The other end of this latter coil is connected through lead 102 to a still further terminal of insulator I5. insulating rotor 37 is pivote-d to insulator I5 for movement between two positions. Rotor 37 carries suitable jumpers to connect the insulator terminals whereby the coils are either series or parallel connected depending upon whether 6V. or IZV. appears at terminal 106. rThus, an electric circuit is established whereby electricity is conducted by the lead 165 through tne heater coils and lead i531 to contact 311. Thence to the switch arm 3) and bracket 22 to magazine lo@ which will be grounded.

The operation of the power or drive means as thus far described is as follows: With the parts in the position shown in FIGURE l, the leg 19 of the bimetallic element 18 rests against stop 23. Bimetal leg 117 is provided with elongated slots Il@ (FIGURE 6) which receive screws 16 thereby enabling bimetal I@ to be moved with respect to bracket leg 15a. Bimetal 1S is moved so that it is tensioned to a predetermined extent equivalent to the amount of movement of the leg I9 which would be effected by the application of a certain amount of heat, say F. This would be a minimum pre-loading of the leg 1.9 in order to set it beyond the point where it would be affected by the temperature of the atmosphere. When the leg I9 has been adjusted as iust stated, carrying the arm' with it, the lower end of the spring holding member 35 is then located in that serration 28 which lies in the vertical plane of the central slot in the switch arm 3d, and the spring holds the switch arm under tension against the on stop 2t) and in engagement with the electric contact 31. Thus, in this position of the parts, electric current will ilow through the circuit already described and cause the resistance coils 38a, Stirb to heat the leg I9 of the birnetallic element 18. As the heat thus applied to the leg I9 rises above 150 F. the leg 19 swings to the right or counterclockwise until it reaches the position shown in FIG- URE 2.

As a result of such movement of the leg 19, the arm Z7 is also moved in the same direction and carries the llower end of the spring 32 with it until it reaches that position (the position shown in FIGURE 2) at which point the pull of the spring 32 on the switch arm 30 causes the latter to rock with a snap action to the position shown in FIGURE 2 where it cornes to rest against the ott stop 2.1. This movement of the switch arm 3) sweeps it out of engagement with the Contact 31, breaking the electric circuit, whereupon the application of heat to the leg i9 ceases and the latter cools off. In cooling, the leg 19 gradually resumes its initial position, moving back into contact with stop 23. In so moving, it carries the arm 27 and the lower end of the spring 32 with it and as it comes to rest against stop Z3, spring 32 has been moved far enough to exert a pull to the left causing the switch arm to rock back against the on stop 2d and into engagement with the electric contact 31. This reestablishes the electric circuit and the operation of the parts due to the application of heat to the leg 19 as just described is repeated. Such intermittent operation of the power unit continues for so long a time as electric current is available to flow through the circuit from terminal 106 to ground.

The driven means is, in eiect, an accumulator, and in the present instance it is shown in its simplest form as comprising a primary ratchet wheel formed on its periphery with teeth 11, the ratchet wheel d@ being mounted for rotation on post 42 secured to the wall 13. Power transmission means in the form of a pawl 43 is formed at one end of arm 2'?. Pawl 43 is rockable about member 25 as a pivot, and has its free end bent to form a nose 43 adapted to engage between the teeth 41 on the ratchet wheel 41?. The spacing of the teeth 41 is such that each movement of the leg 19 during the application of heat thereto will move the ratchet wheel 4t) a distance equal to the pitch of one tooth, and when the leg 19 upon cooling retums to its initial position against stop 23, pawl i3 is carried with it and the nose 45 thereof rides over and drops in front of the succeeding tooth on the ratchet wheel 411.

Holding pawl i6 is adjustably mounted by a slot and screw connection 47 in xed position on bracket 44. Pawl 46 is so that a biturcated member with the bent over free end or nose i3 of one leg 46a engages behind one of the the teeth i1 on the ratchet wheel 411. Each time the ratchet wheel 40 is moved a distance of one tooth by the power transmission pawl 43, the nose 4S of leg 46a rides over one tooth i1 and drops behind it to prevent reverse rotation of the ratchet wheel di) when the pawl i3 is carried to the lett upon the cooling of the leg 19 of the bimetallic element 18. Thus, during each heating-cooling cycle ot' bimetal, the ratchet wheel d@ is rotated a distance equal to the pitch of one tooth and held in that position.

Cup-like member 110 is secured to the underside of wheel lit) by means of three peened over ears 111 extend-` ing through apertures of wheel 4t). Member 11d is provided with three radical extensions 112 each having a downwardly turned ear 113 at the free end thereof. Ears 113 are so positioned that upon rotation of wheel 41! ears 113 engage one end of crank 115.

Crank 115 is pivotally mounted at pin 116 to bracket 44. Pawl 117 is pivotally mounted at one end thereof to rivet 113` carried by crank 115 while the other end of pawl 117 is biased toward engagement with teeth 118 at the periphery of auxiliary ratchet wheel 120 by means of spring 121. Spring 121 is a torsion member mounted to pin 116 with one end bearing against pawl 117 and the other bearing against crank 115 in a manner such that pawl 117 is biased clockwise about its pivot 118 with respect to FIGURE l and crank 115 is biased counterclockwise about its pivot 116 with respect to FIGURE 1. The engagement of crank 115 with bracket dit at point 122 limits counterclockwise movement of crank 115.

Pawl 43 is arranged so that the deiiection of bimetal section 19 causes counterclockwise rotation of main ratchet wheel 40 about post 42 as a center. wheel 46 carries member 11d in a counterclockwise direction. For each 1/3 revolution of wheel 40 an ear 113` of member 110 engages crank 115 moving the same clockwise about its pivot 116 against the force of biasing spring 121. As crank 115 is moved clockwise pawl 117 is moved upwardly with respect to FIGURE 1 thereby advancing auxiliary ratchet wheel 121i in a counterclockwise direction with respect to FIGURE 1. The elements hereinbefore described are so proportioned that the engagement of each of the ears 113 with crank 115 causes auxiliary ratchet wheel 120 to be advanced by the angular spacing between one tooth thereof.

Ratchet ltion of this wheel.

The other leg 15b of holding pawl i6 is in engagehandle 125 projects beyond the boundaries of wall 13 through a slot in cover 125 so as to be accessible tor manual operation when cover 126 is in closed position. Cover 126 is mounted to housing 1de by means of thumb screw 127 which is received by the threaded aperture at the free end of post 42. Extension 12S of rotor 37 extends through cover slot 129 so that rotor 37 is operable with cover 126 in place.

Mounted below auxiliary ratchet wheel 120 and keyed thereto is cam member 131i. The latter comprises two identical cams, each extending for 18() degrees. As auxiliary ratchet wheel 121B is rotated counterclockwise these cams successively engage follower extension 131 of actuator arm 132 and in so doing gradually moves arm 132 clockwise about its pivot 133. Torsion spring 131i mounted to pivot pin 133 is anchored at one end 135 to wall 13 while the other end 136 of spring 1311 bears against tab 137 of arm 132 thereby biasing arm 132 counterclockwise with respect to FIGURE 1. As actuator arm 132 is moved clockwise, energy is restored within spring 131i-, At such time as the high spot 141 of the cam passes follower edge 155-2 the sharp drop oli of the cam brings about the sudden release of the energy stored in spring 134. The tree end of arrn 132 is provided with an oii'set portion 11d which extends through slot 145 of wall 13 into housing 1111). Oitset portion 141i is provided with a down-turned pusher extension 146 as will be more fully explained hereinafter.

The wall of housing 1h13 opposite wall 13 is an openable cover 1417 hinged at 14S and maintained in closed position by thumb screw 149. Cover 147 carries two coil springs 151 each of which is conical in appearance when extended. That is, the top spiral (with respect to FIG- URE 4) is considerably smaller than the bottom spiral so that springs 151 may be compressed to a very low prole. The lower ends of springs 151 are secured to cover 147 while the upper ends are secured to plate 152 which extends generally parallel to cover 1417.

Springs 151 bias plate 152 against card stack 153. Stack 153 comprises a plurality of service indicating cards 154 arranged in a programmed sequence. Each of the cards 154 is provided with a keying notch 155. That is, card 15d is generally rectangular and notch 155 is asymmetrically positioned along one of the long edges thereof. Notch 155 cooperates with the keying formation formed by bracket 156 to insure that stack 153 is in predetermined orientation when disposed within housing 1115i. Bracket 156 is secured to one of the housing side walls and is symmetrically positioned therealong.

Actuator arm pusher extension projects into housing 111th by a distance equal to slightly less than the thickness of card 154. With actuator arm 132 in its most clockwise position with respect to FIGURE l, extension 146 is positioned to the rear ot the card. 154 adjacent to wall 13. Upon the sudden release of the energy stored in spring 34, actuator arm 132 moves rapidly in a counterclockwise direction with extension 14d engaging the top most card 15d driving it in the direction of arrow A in FIGURE 4 (arrow B in FIGURE 6) through slot in housing end wall 151 with slot 150 being positioned adjacent to wall 13. Extension 146 is provided with a knife edge 14611 (FIGURE 9A) which bites into the trailing edge ot card 154i to provide positive control thereof during the ejecting strike.

In the device illustrated slot 15@ is slightly wider than the thickness of a single card 154 but narrower than the combined thicknesses of two of the cards 154. Of course, if desired, slot 1511 and pusher extension 145 may be so proportioned that any predetermined number of cards may be ejected simultaneously.

Hold-back spring 161i is secured by rivets 161 to keying 3,202 are t bracket 156 and is positioned Within the space between bracelet 156 and the wall of housing 1% to which bracket 156 is mounted with spring portion 162 being biased against the inner surface of wall 13. Spring portion 162 is also positioned within the keying notch of card 154 so that as the top most card in the stack is being ejected by the action of actuator arm 132 spring portion 162 blocks movement of this card.

Spring portion 162 is so positioned and slot 145 is so shaped that the notch and boundary 164 will not engage spring portion 162 until a time after card 15d is not being driven by actuator arm 132. rl`hus, spring 1619 will arrest outward movement of card 154 when the latter is only partially ejected from housing 1%. In this position card 154 is conspicuous, thereby indicating that some form of servicing is due. When the serviceman comes to service the machine he may readily withdraw the partially ejected card 154 from housing 161i. The action of springs 151 forces the top card remaining in stack 153 against the interior surface of wall 13 and the process previously described is repeated.

1t is noted that after ejection of one card 1541 it is not necessary to reset the device. That is, operation for cloclc ing the next servicing time commences immediately upon the partial ejection of one card even before this card is removed by the serviceman.

The device hereinbefore described is normally mounted to mounting plate 1713 with the latter being secured by `screws 171, extending through apertures 172, to a grounded member. Mounting plate 171B is somewhat rectangular with offset inwardly turned lips 173 at the long edges thereof. Cover 147 of housing 11i@ is provided, along its long edges, with outwardly turned anges 1741. Hons ing 16th is mountable to plate 17@ by sliding flanges 174- below ears 173 in the direction of arrow C (FGURE 7) When housing 1131i abuts plate stop 175, housing terminal 1% is in engagement with terminal 176 which` is connected through lead 177 connected to one terminal of an electrical energizing source. The other terminal of the energizing source is connected to the same ground as screws 171. Terminal 176 is mounted to insulating sheet 178 which in turn is mounted to the upward extension 179 of mounting plate 17d. The extensive area of engagement between flanges 174- and ears 173 provides one electrical connection between plate 17@ and housing d while the engagement between terminal contacts between 1tl6 and 17e provides the other electrical connection.

FIGURE 8 illustrates a typical hookup for a service indicator as hereinbefore described when utilized in connection with an internal combustion engine. In this hookup one terminal of service indicator is grounded while the other terminal is connected through lead 1116 to one contact of normally open ignition switch 291. The other contact of switch 261 is connected to the negative ter minal of battery 262 whose other terminal is grounded. The ungrounded terminal of ignition system 2153 for motor 2&4 is connected through lead 295 to lead 1%.

1t is seen .that service indicator 21M) is energized only when ignition 2193 is energized and that indicator 2116 functions to record the servicing interval independently of the speed of engine 2114.

It is notedthat bimetal 18 is so constructed with respect to the other elements of this invention that the cooling portion of the bimetal heating-cooling cycle is much longer than the heating portion of this cycle. Typically the lcooling period is from 2/3 to Vs of the entire heating-cooling cycle. Because of this, in extremely cold weather the heating-cooling cycle will be much shorter than the heating-cooling cycle during hot weather. As previously explained, this is very desirable inV that machines of the type being protected must be serviced more often during the winter than during the summer.

Ait is .also noted that pre-loading of bimetal 18 is accomplished by adjusting .the position of anchoring leg 17.

rlhus, stop 23 is a iixed point of reference for the free end of the bimetal when the latter is cold so that bimetal 13 always moves pawl 43 through the same distance before switch arm 30 engages stop 21.

Thus, this invention provides a novel construction for a service indicating device in which cards 154, arranged in a programmed sequence within lstack 153, are partially ejected through the action of actuator arm 132 to indicate that servicing is required. Cands 154, in addition to carrying service indicating instructions may also be provided with apertures `arranged in a coded sequence corresponding to the servicing instructions and identification for the vehicle being serviced. After the servicing instructions have been carried out the card is utilized to facilitate billing and/ or statistical procedures.

While this invention has been described in connection with automotive engines that are operated in conjunction with an electrical source to drive the power unit a mechanical counter can be used to drive cam means 36. 1n the latter event appropriate switch means operated by arm 132 can be used to deactivate an automatic machine after `a predetermined number of articles have been produced by the machine. Manually operated member 1.24 is then used to advance cam means 131) and back oif arm 132 suiliciently to deactivate the switch means and permit the machine to be operated. During the time the machine is not operated servicing or changeover procedures may be performed.

Although I have described .preferred embodiments of my novel invention, many variations and modifications will now be obvious to those skilled inthe art, and I prefer therefore to be limited not by the specific disclosure herein but only by the appended claims.

The embodiments of the invention in which an exclusive privilege or property is claimed are defined as follows:

1. A service indicator comprising a drive means, an electric circuit which when closed and energized actuates said drive means, an actuator means driven by said drive means, a compartment, a stack of cards disposed within said compartment, said cards arranged in a programmed` sequence, said actuator means having a part in engagement with a card at a first side of said stack, means energized by said drive means for operating said actuator means through a complete uninterruptable positive feed stroke after a predetermined operation of said drive means, said actuator means when operated positively driving said card forward along a feed path to a position in which saidV card is partially ejected from said compartment through an opening therein to a position Where the card will remain for an indefinite periodprior to complete removal of the card from the compartment and additional means in engagement with said stack for moving the next card following said card into alignment with said opening after said card has been completely removed from said compartment.

2. The service indicator of claim 1 in which the drive means includes. a bimetallic strip heated by the passage of current through said electric circuit.

3. The service indicator of claim 2 in which the strip has an anchored end and a free deflectable end, a stop against which said free deilectable end rests when said strip is cool, and means for adjusting the position of said anchored end thereby pre-loading said strip by applying a force against said free end directedrin the direction in which said free end deflects when said strip is heated.

4. The service indicator of claim 2 in which the bimetallic strip is operated in a heating-cooling cycle, saidl cycle being divided into a cooling and a heating portion, said cooling portion being materially longer than said heating portion.

5. The service indicator of claim 1 in which the means energized by said drive means comprises a spring which biases the actuator means in a direction to positively drive a card forward through the opening in the compartment.

6. The service indicator of claim 1 in which there is a hold back device which engages said cards as they are being ejected and limits the extent to which said actuator means ejects said cards from said compartment, each of the cards of said stack being of identical peripheral configuration.

'l". The service indicator of claim l in which the cards are each provided with an assymetrically positioned keying notch, means defining a keying formation Within said compartment which cooperates with said keying notch to `assure proper orientation of said cards within said cornpartment.

S. The service indicator of claim 7 in which there is a hold back device which engages said cards as they are being ejected and limits the extent to which said actuator means ejects said cards from said compartment.

9. The service indicator of claim 8 in which the hold back device comprises a member which extendsV into said keying notch, said member being deilectable to permit total removal of partially ejected cards.

10. The service indicator of claim 4 in which the cooling portion is in the range of from S to %s of the cycle at an ambient temperature of 20 C.

11. The combination comprising a compartment having an openable cover, a stack of cards within said compartment, means biasing said stack away from said cover, said compartment including rst means defining an opening, second means for ejecting a predetermined number of cards located on the side of said stack remote from said cover through said opening, said opening being too narrow to permit passage of said predetermined member of cards plus one and additional means in engagement with said stack for moving the next predetermined number of cards into alignment with said opening after said predetermined number of cards have been completely removed from said compartment.

12. The combination comprising a compartment having an openable cover, a stack of cards within said compartment, means biasing said stack away from said cover, said compartment including first means defining an opening, second means for ejecting a card located on the side of said stack remote from said cover through said opening, saidopening being too narrow to permit passage therethrough of more than one card at a time, and additional means in engagement with said stack for moving the next 10 card following said card into alignment with said opening after said card has been completely removed from said compartment.

13. The combination of claim 12 in which the biasing means comprises a compression spring having one end aiiixed to said cover, a plate carried by said spring at the other end thereof, said plate bearing against said stack.

14. The combination of claim 12 in which the biasing means is carried by the cover and is comprised of a coil spring whose spirals gradually diminish in size from one end to the other of said spring.

15. The combination of claim 12 in which the second means comprises a member having a knife edge operatively positioned to engage the tr-ailing edge of the card being ejected.

16. A service indicator comprising a drive means, an electric circuit which when closed and energized actuates said drive means, an actuator means driven by said drive means, a compartment, a stack of cards disposed within said compartment, said cards arranged in a programmed sequence, said actuator means having a part in engagement with a card at a first side of said stack, first means energized by said drive means for operating said actuator means after a predetermined operation of said drive means, said actuator partially ejecting said card from said com- .partment through an opening therein, to a position where the card is remote from a means which will completely remove the card from the compartment, said drive means automatically energizing said rst means following operation of said actuator, each of the cards of said stack being of identical peripheral configuration.

References Cited by the Examiner UNITED STATES PATENTS 2,009,601 7/ 35 Anderson. 2,294,031 8/42 Hobbs et al. 58-146 2,364,999 12/44 Parr et al. 2,540,930 2/51 Campbell et al. 221`96 FOREIGN PATENTS 369,649 3/ 32 Great Britain.

RAPHAEL M. LUPO, Prmay Examiner.

HADD S. LANE, Examiner. 

1. A SERVICE INDICATOR COMPRISING A DRIVE MEANS, AN ELECTRIC CIRCUIT WHICH WHEN CLOSED AND ENERGIZED ACTUATES SAID DRIVE MEANS, AN ACTUATOR MEAN DRIVEN BY SAID DRIVE MEANS, A COMPARTMENT, A STACK OF CARDS DISPOSED WITHIN SAID COMPARTMENT, SAID CARDS ARRANGED IN A PROGRAMMED SEQUENCE, SAID ACTUATOR MEANS HAVING A PART IN ENGAGEMENT WITH A CARD AT A FIRST SIDE OF SAID STACK, MEANS ENERGIZED BY SAID DRIVE MEANS FOR OPERATING SAID ACTUATOR MEANS THROUGH A COMPLETE UNINTERRUPTABLE POSITIVE FEED STROKE AFTER A PREDETERMINED OPERATION OF SAID DRIVE MEANS, SAID ACTUATOR MEANS WHEN OPERATED POSITIVELY DRIVING SAID CARD FORWARD ALONG A FEED PATH TO A POSITION IN WHICH SAID CARD IS PARTIALLY EJECTED FROM SAID COMPARTMENT THROUGH AN OPENING THEREIN TO A POSITION WHERE THE CARD WILL REMAIN FOR AN INDEFINITE PERIOD PRIOR TO COMPLETE REMOVAL OF THE CARD FROM THE COMPARTMENT AND ADDITIONAL MEANS IN ENGAGEMENT WITH SAID STACK FOR MOVING THE NEXT CARD FOLLOWING SAID CARD INTO ALIGNMENT WITH SAID OPENING AFTER SAID CARD HAS BEEN COMPLETELY REMOVED FROM SAID COMPARTMENT. 